Consider
that effective writers sometimes intentionally
repeat words and phrases whereas ineffective writers often repeat words
and phrases unintentionally. Intentional repetition helps to emphasize important
information or relationships, that is, it creates a rational pattern. In
contrast, unintentional repetition creates patterns that lack sense (the
patterns do not convey information). Unintended repetition is ineffective
because the attentive reader will waste time trying to understand the sense
underlying the repetition. Inattentive readers will not notice repetition.
If you are writing for inattentive readers, you don't need my advice.

Here
are some common words or terms that are ineffectively repeated at the start
of sentences: